Friday, 10 December 2010

It's not going to flood....

We are experiencing a fairly rapid thaw of the snow in the Wansbeck catchment. Apparently it's nothing to worry about, though.

The last time there was a flood in Morpeth because of snow melt was in March 1963. Then there was twice as much snow, it melted over 2 to 3 days and it was accompanied by heavy rain. And the ground was frozen so it couldn't soak up any of the melt.

Today there is only the equivalent of 3" of rain held in the snow, there is no rain forecast and it will probably take 2-3 days at these temperatures for a total melt (we are in December, not March, so the average temperature is a lot lower).

75mm of rain over 3 days equates to approximately 1mm/hr. We are told that the Wansbeck can cope with more than 4mm/hr before there is any worry of possible flooding - even before the flood alleviation measures are built. For it to flood ALL the snow would have to melt within 15 hours and enter the river!

I'm told that the river level may rise a foot or so, but that is all.

Watching the water level....

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